1. Field of the Invention
The present invention relates generally to a cassette case for containing several tens of disk cassettes or the like each containing, for example, a 3.5 inch floppy disk and, more specifically, to a cassette case that has individual compartments containing a number of cassettes.
2. Description of the Background
There has been proposed a cassette containing case as shown in FIGS. 9 to 13 that can store several tens of disk cassettes, each containing a 3.5 inch floppy disk. That cassette containing case is made of a plastic resin and includes a cover box 1, which serves as a pedestal when opened, an outer box 2, and an inner box 3. The cover box 1 has right and left side plates 11, a top plate 12, and a front surface plate 13, which has a height about one-half that of the right and left side plates 11 and is arranged contiguously with the top plate 12. The cover box thus formed provides at least two open areas 14 and 16. The outer box 2 has right and left side plates 21, a back surface plate 22, and a bottom plate 23. The outer box thus formed defines a main open area 24. The inner box 3 includes right and left side plates 31, a front surface plate 32, and a central partitioning plate 33. The inner box 3 is formed to have a height around one-half that of the outer box 2.
In assembling such a plastic case, the outer box 2 is inserted within the cover box 1, and the portions near the lower ends of the right and left side plates 21 of the outer box 2 are rotatably mounted on the inner sides of the lower ends of the right and left side plates 11 by a pair of right and left supporting pins 4 formed integrally with the right and left side plates 11. The inner box 3 is inserted within the outer box 2, and the lower end of the front surface plate 32 of the inner box 3 is rotatably mounted on the leading edge of the bottom plate 23 of the outer box 2 by means of a hinge 5. In addition, a pair of right and left guide pins 6 and corresponding arcuate slots 7 for restricting the extent of rotation of the inner box 3 are formed between the right and left side plates 21 of the outer box 2 and the right and left side plates 31 of the inner box 3 in such a manner as to be freely fitted to each other.
The cassette case can be assembled and closed to form a perfect closed box, as shown in FIG. 9. In that position, the front surface plate 32 of the inner box 3 is fitted to the opening 16 of the cover box 1, and the cover box 1 is locked to the outer box 2 at a locking portion (not shown).
In such an assembled closed state as shown in FIG. 9, a locking releasing portion 8 is depressed to release the locking between the cover box 1 and the outer box 2. After that, as shown in FIG. 10, the cover box 1 is rotated by 90 degrees around the supporting pins 4 in the direction of arrow a, to an opened position. Subsequently, as shown in FIGS. 11 and 12, the cover box 1 is rotated further by about 200 degrees around the supporting pins 4 in the direction of the arrow a, to reverse the direction of the cover box 1 relative to FIGS. 10 and 11. The outer box 2 is thus relatively inserted in the open area 16 of the cover box 1, and the back surface plate 22 of the outer box 2 is abutted on the front surface plate 13 of the cover box 1. Consequently, the outer box 2 is stably supported on the cover box 1, with the cover box 1 serving as pedestal, and with the outer box in an attitude inclined backward in the direction of the arrow c'. This kind of cassette containing case is intended to be placed on the top of a desk or similar surface.
As shown in FIG. 11, ten to fifteen disk cassettes 9, each containing a 3.5 inch floppy disk, can be inserted in each of a pair of right and left cassette containing portions 10a and 10b formed respectively on both sides of the central partitioning plate 33 between the outer box 2 and the inner box 3 along the direction of arrow b.
In retrieving and taking out a disk cassette 9 contained in either of the right and left cassette containing portions 10a and 10b, the inner box 3 is rotated around the hinge 5 forward in the direction of the arrow c with respect to the outer box 2, and is opened in an approximately inverted trapezoid shape with respect to the outer box 2, as shown by the broken line in FIG. 12 and also in FIG. 13. In that position, the guide pins 6 and the arcuate slots 7 cooperate to restrict the extent of rotation of the inner box 3 in the direction of the arrow c.
While this proposed arrangement appears to provide a serviceable unit, the pair of right and left cassette containing portions 10a and 10b being integrally formed on the right and left sides of the central partitioning plate 33 of the inner box 3 brings about the following disadvantage. Namely, in retrieving and taking out a required cassette 9 in the state that a large number of cassettes 9 are stored in the right and left containing portions 10a and 10b, as shown in FIGS. 12 and 13, as soon as the inner box 3 is opened forward in the direction of the arrow c with respect to the outer box 2, many of the cassettes 9 will fall forward in the direction of arrow c. This causes the gravity centers of the outer box 2 and the inner box 3 to be displaced making the assembly unstable. As a result, the outer box 2 and the inner box 3 tend to occasionally fall forward around the right and left supporting pins 4 in the direction of the arrow c with respect to the cover box 1.
Further, as shown in FIG. 13, when the inner box 3 is opened in the direction of the arrow c with respect to the outer box 2, large numbers of the disk cassettes 9 contained in the right and left cassette containing portions 10a and 10b will both fall forward in the direction of arrow c. Consequently, when the disk cassette 9 within one cassette containing portion 10a is retrieved and taken out, it is obstructed by the disk cassettes 9 within the other cassette containing portion 10b. Thus, there occurs the disadvantage such that the cassette 9 is difficult to handle when it is retrieved and taken out in the case that there are large numbers of cassettes contained in the opened cassette case.